Field of the Invention
The present invention relates to the field of circuit breakers for low voltage electric lines (i.e. with a voltage of less than 1 KV) of a single-phase or three-phase type.
In particular, the invention refers to a low voltage circuit breaker with a control device for re-closing said low voltage circuit breaker, for example a residual current circuit breaker or a miniature circuit breaker.
Description of Related Art
As is known, a low voltage circuit breaker is a device that can assume two distinct operating configurations.
In the closed configuration, the electrical contacts of the circuit breaker are coupled so as to enable the passage of current along the electric line the circuit breaker is operatively associated with.
In the open configuration, the electrical contacts are separated and the passage of current along the electric line is interrupted.
The switching of the circuit breaker from the closed configuration to the open configuration (opening manoeuvre) can be done manually, by turning a circuit breaker operating lever. Alternatively, the opening manoeuvre can be carried out automatically by an uncoupling relay separates the electrical contacts following receipt of a command signal or when particular operating conditions in the electric line are detected, such as the presence of an earth leakage current, for example.
In certain types of circuit breakers, the switching of the circuit breaker from the open configuration to the closed configuration (closing manoeuvre) can only be done manually, by turning the circuit breaker lever in the direction opposite that used for the opening manoeuvre.
Other types of circuit breakers have automatic re-closure of the contacts, when this is permitted by the operating conditions of the electric line.
In this case, the circuit breaker closing manoeuvre is performed automatically, thanks to the action of a control device, operatively associated with the circuit breaker manoeuvring lever. There are also types of circuit breaker that feature the remote re-closure of the contacts, thanks to a rearming lever operatively associated with the circuit breaker manoeuvring lever. This rearming lever may be in turn operatively associated with a control device, in a remote position with respect to the body of the circuit breaker.
Patent applications EP1505620 and EP1870919 describe several known examples of control devices for re-closing low voltage circuit breakers.
These devices comprise a servo-mechanism adapted to pilot a rearming lever, in turn operatively associated with the circuit breaker, between two predetermined positions, each of which is associated with an operative configuration of the circuit breaker.
Currently available control devices for re-closing circuit breakers present certain disadvantages, mainly associated with a relatively complex, bulky structure that is relatively expensive to produce industrially.
Installation of current control devices is often laborious, particularly when the space available for installation is relatively limited, such as in small electrical cabinets.